For medical reasons, I don't bake with baking powder. I use a substitute. For 1 teaspoon, I use 1/4 teaspoon baking soda & 1/2 teaspoon cream of tartar.
Today, I made a Lemon Loaf Cake from Cook-Ahead Cookery. It doesn't call for salt. This was the first time I made it with the baking powder substitute. I became concerned that I needed salt to activate either the soda or the tartar. I didn't want to mess up a lovely recipe, but I threw in 1/8 teaspoon salt.
Do either baking soda or cream of tartar need salt to work?